VOLUMES OF ACTIVATION FOR THE MERCURY(II) INDUCED AQUATION REACTIONS OF HALOPENTAAMMINECOBALT(III), RHODIUM(III) AND CHROMIUM(III) IONS IN ACIDIC AQUEOUS-SOLUTION

The pressure dependencies of the rates of Hg(II) induced aquation of Co(NH3)5Cl2+, CoNH35Br2+ Cr(NH3)5Cl2+, and Rh(NH3)5Cl2+ were studied at 15°C, with the exception of the latter which was investigated at 25°C, and a [H+] of 0.31 M with μ = 0.6 M. The respective volumes of activation were found to be -1.7 ± 1.0, +0.8 ± 0.5, +0.7 ± 0.4, and -1.0 ± 0.4 cm3 mol-1. These results are discussed with reference to the numerous conventional kinetic data in the literature, further establishing a D-mechanism for the rate-determining step. © 1979.